package thread;

class Counter {
    private int count = 0;

    synchronized public void add() {
        count++;
    }

//    public void add() {
//        synchronized (this) {
//            count++;
//        }
//    }

    public int getCount() {
        return count;
    }
}

public class Demo18 {
    public static void main(String[] args) throws InterruptedException {
        //Object lock = new Object();
        Counter counter = new Counter();
        Thread t1 = new Thread(()->{
            for (int i = 0; i < 50000; i++) {
               // synchronized (lock) {
                    counter.add();
               // }
            }
        });
        Thread t2 = new Thread(()->{
            for (int i = 0; i < 50000; i++) {
               // synchronized (lock) {
                    counter.add();
               // }
            }
        });

        t1.start();
        t2.start();

        t1.join();
        t2.join();

        System.out.println("count = " + counter.getCount());

    }
}
